Its two 25cm tusks made Odobenocetops look like a cross between a walrus and a manatee. In males only, the right hand tusk grew much larger - up to 1.35m long. It didn't have any teeth.

It cruised in shallow water staying close to the seabed where it was safest. One species had an echolocation organ, similar to that of modern dolphins.

By grubbing around in the mud, Odobenocetops found worms and shellfish to eat. Muscular lips allowed it to suck clams out of their shells.

Odobenocetops was an air-breathing mammal so had to rise to the surface in between dives. It used its powerful tail to swim around. It had good eyesight but despite its size, Odobenocetops had little defence against sharks. The tusks were not strong enough to be much use in a fight.